Boring machine



y 1944- v J. SUNNEN 2,350,081 BORING MACHINE Original Filed Feb. 3, 19402 Sheets-Sheet 1 INVENTOR JO SEPH SUNNEN ATTORNEY y 1944- J. SUNNEN2,350,081

\ BORING MACHINE Original Filed Feb. 5, 1940 2 Sheets-Sheet 2 VENTORTTORNEY JOS H SUNNEN Patented May 30, 1944 OFFICE BORING MACHINE JosephSunnen, Clayton, Mo.

Original application February 3, 1940, Serial No. 317,074. Divided andthis application October 16,. 1941, Serial No. 415,154

4 Claims. (o1. was) This invention relates to machine tools andparticularly to centering devices for connecting rod boring machines.The machine for which the device is primarily designed is especiallyintended for boring out the big ends and bearing shells of connectingrods for internal combustion engines and finishing or refinishin them toan exact specified dimension, but it will be understood that the devicemay be applied to ma chines used for other purposes, and numerousmodifications of the specific structure shown may be made within thescope of the invention.

The main feature of the invention claimed herein is the provision of anew and improved centering device for centering the work with respect toa boring bar or other working tool.

This application is a division of my previous application Serial No.317,074, filed February 3, 1940.

The invention will be better understood, and: other objects andadvantages will appear from the following description and accompanyingdrawings, referring to which:

Fig. 1 is a longitudinal sectional view of the work holding and feedingmechanism and the boring bar in connection with which my invention is tobe used.

Fig. 2 is a detail view, showing the bayonet joint mechanism for holdingthe boring bar in the spindle.

Fig. 3 is a detail sectional plan view, taken along the section line 33of Fig. 1, showing the feed mechanism.

Fig. 4 is a cross sectional view of the spindle and boring bar, takenalong the section line 4-4 of Fig. 1.

Fig. 5 is a cross sectional view, taken along the section line 55 ofFig. 1'.

Fig. 6 is a cross sectional view, taken along the section line 6-6 ofFig. 1.

Fig. 7 shows the centering device which I provide for quickly andaccurately centering the connecting rod with respect to the spindle,parts being in section and others broken away.

Fig. 8 is another view of the centering device, showing parts of thework holding mechanism, spindle, and the rod which is being centered.

Fig. 9 is a cross sectional view taken on the section line 99 of Fig. 8.

The spindle 20 of the boring machine in connection with which the deviceis used is provided with a longitudinal bore having an enlarged portionat the front end and a shoulder 23 against which is seated aplate 24which is provided with an eccentric opening to receive the tool controlplunger 25. This plunger is mourit -l ed on a shaft 26, which is axiallymovable for the purpose of adjusting the tool 53. The plunger isnormally held in retractedposition by any suitable means. This functionis at least partially performed by the spring 82', but supple mentarymeans may be added if desired. The

shaft 28 is adjustable toth'e ri'ght'orleft with respect to Figure 1 byany suitable means (not shown) for the purpose of advancing orretracting cutting tool 53.

The work, which may for instance be a con necting rod 40, is mounted mework holding mechanism or chuck which is rotatably and slidably mountedon spindle-extension 4| having a bore accurately fitted to thecylindrical surface of the spindle extension and having a flange or faceplate 43 against which one end of the work" is to be clamped. The chuck42 is provided with an adjustable clamp 46 which carries transversescrews 41 threaded into the ring-shaped clamp 46 as indicated at48. Thework is held in posimembers 50 as indicated at 52.

to boring rods of widely different sizes.

With the work held in the chuck, as shown. in Fig. 1, the cuttingtool53' is rotated by the spindle and boring bar and the cylindrical boringis. accomplished by sliding the chuck 42* along the spindle extensionwhile manually holding thechuck and the work against rotation. The feeding of the chuck along the spindle extension 4| is accomplished by meansof the roller 54.- This roller is mounted on a ball bearing 55 which isfixed on the shaft 56. This shaft is loosely carried in a bore 51 formedin the body member,

and the inner end of the shaft is provided with a spherical section 58,having a recess at one side.

to receive the point of the locating screw 59. adjusting screw ismounted at one sideof the shaft 56' and a spring 6| is held in positionto oppose the action of the screw 60 by means of a screw plug 62. Aswill be seen by reference to Figs. 1 and 3 the axis of the shaft 55 androller 54 may be adjusted into or out of parallelism with the axis ofthe spindle extension 4| in eithe direction by adjusting the screw 60. aThe roller 54 may be pressedinto contact with the spindle extension 4|by the plunger Bill which is controlledby the spring 620 and a Pressureon the manually. operated lever 63.

lever 53 forces the plunger 6H] into contact with the shaft 56 therebycausing it to ride firmly on the spindle 4|, the friction beingsufficient to drive the chuck along the spindle extension during therotation thereof.

As long as the axis of the roller 54 is parallel to the axis of thespindle extension relative rotation between the spindle extension andthe chuck 42 merely produce rotation of the roller ,54, but when thescrew 60 is adjusted to throw the axis of the shaft 56 out ofparallelism with the axis of the spindle 4| as indicated in Fig. 3rotation of the spindle 4| while the chuck :42 is held stationaryproduces a relative feeding of the chuck along the spindle so thattheboring tool 53 can be fed regularly through the rodor shell which isbeing bored.

In order to prevent the chuck too far to the left with respect to Fig. 1which would result in the boring tool 53 boring into-the flange 43 Iprovide a circular grooveor shoulder and aspring pressed plunger '65normallyheld incontact vwith the; spindle extension 4! by the coverplate 366 and spring 61. 'This plunger 65 mayberheld against rotation byany-suitable means such as a key-way (not shown) and is provided-with ashoulder conformed to the shoulder:64tojlimit the movement of thechuck-along thespindle extension. A greasemack 68 held in contactwith'the spindle-extension by the light spring 69 may also be provided.-Thecboring'bar Ilia-fitted into the bore of the spindle extension andisquicklyattachable o-rdetachable, by means oflthebayonetjointconstruction H engaging'the pin 12-;which is mounted inthe spindleextension 4|. 'The'borlng bar is longitudinallyslotted at one sidetozreceive-the tool control cam 14. This member is provided with ahead'15 having-a; cam surface .16 which extendsthrough the slot 11 inthe :boring'too'l andslidably contacts the bottom ofthe. slot and-movestoward the work against thezpressure .of thespring l8 whichhas one endrigidly mounted 'in the boring bares-indicated at"|.9 and the otherrendprojecting into-an openinglfilliin the boring tool. 'The spring tends towithdraw the boring-tool. and its action is limited by the. cam.suriacei'lfi. Sl-idably mounted. in the rear end ofthe boringbar is-aplunger 8| which is biased toward theiright'withrespect to Fig. 8 bymeans of the compression spring 82. The plunger 8| .is provided with-a-plurality of longitudinally spaced notches 83 toreceiveprojection.8l4 at the rear-end of the tool-operating member 114. Byselectively locatingthe projection'84inthenotchesB3, ,a wide rangeofradial movement cf :the tool .153 is obtainable. The plunger 8| contactsthe end of the tool controlling plunger :25 and is longitudinally:movable withxrespect to the boring-bar.

After boring a trial hole inthe connecting, rod 4flrthe.operator stopsthe spindle and withdraws the boring bar by rotating it manually inaclockwise direction about. a, quarter turn which'disengages thebayonetslot. Asthe bar is withdrawn spring- 82 withdraws the. cam headand allows the withdrawal of the boring tool-by the spring 18,thusfurther insuring that there will be no scratching of thesurfaceof'the hole. by the tool. The-bar is then withdrawn from't hespindle extension and-the'hole, may beinspected and measured.

The originalcentering of the rod which is to be bored with respect tothe chuck and spindle is-accomplished with the aid of the centering toolwhich is best shown in Figs. 7, 8 .and 9. Thecen- 42 being moved teringtool comprised a cam body member 86 having a shank 81 accuratelyfinished to slidable fit in the bore of the spindle extension 4| whenthe boring bar 19 is removed. The outer end of the centering tool isprovided with a knurled handle 88 and shoulder 89 having a taperedextension 99. Between the tapered portion and the shank 81 threelongitudinal slots 9| are formed to receive the jaws 92 which areresiliently held in position by the circular coil spring 93.

The slots 9| are tapered at the bottom on an angle which is thesupplement of a similar angle at the inside of the centering jaws 92,and the jaws are so formed that as they are moved along the shank to theright or left with respect to Figs. 7-and 8 the inner side of the jawsis held in contact with the bottom of the slots 9| by the spring 93 andthe outer edges of the jaws are equidistant from the axis of thecentering tool. A sleeve 94 is slidably mounted on the shank 81 andarrangedto contact the endsof the jaws 92150 as to-slide them along thecam surface at the bot tom of the slots'9l.

The connecting rod'49-being placed in juxtaposition to the flange member43 and with its big end bore manually aligned with the opening'inthe-endthereof, the shank B7 of the centering tool is inserted in thebore in the spindle extension 4|. It will be understood, of course,that'the boring bar will have been removed for the centering operation.The centering tool is then man-' ually moved into the bore of thespindle sleeve until the sleeve 94 contacts the end of the spindlesleeve. Further movement causes the jaws 92 to be slid upwardly alongthe cam surfaces until position the centering tool is withdrawn and theboring bar is inserted so that the rod may be bored.

I claim:

1. Centering mechanism for boring machines comprising a body memberhaving a substam tially cylindrical surface adapted to be slidablyfitted to a corresponding cylindrical surface.

carried by the spindle of the boring -machine,

said body member having three or more longi-' tudinal grooves, saidgrooves having their. bottoms formed at an angle to the axis of saidbody member, slide members fitting in said grooves and adapted toslidably follow the bottoms thereof during longitudinal movement of saidslidable members along said grooves, a sleeve member at the inner endsof said slidable members, said sleeve member being adapted "to contactthe cylindrical surface of said body member'and to form a contactbetweenthe endof the spindle and the ends of said slidable mem-- bers,the outer edges of said slidable members lying in a surface of rotation,and a spring device for holding said slidable members againstthe bottomof said grooves.

2. Centering mechanism for boring machines comprising a body memberhaving a substantially cylindrical shank adapted to slidably fit thebore of the spindle of the boring machine, three or more equally spacedlongitudinal grooves formed in said body member and extending into saidshank, the bottoms of said grooves being formed at an angle extendingdownwardly as the groove approaches the end of said shank whichis toenter the spindle, slidable members in each of said grooves, saidslidable members having their inner edges in contact with the bottoms oftheir respective grooves, the outer edges of said slidable members beingprovided with a recess, spring device mounted in said recess for holdingsaid slidable members against the bottoms of said grooves and saidmembers being so constructed and arrangedas to be shifted in theirrespective grooves by thrust against the end portion of said spindlewhen said shank is inserted therein.

3. Centering mechanism for boring machines comprising a body memberhaving a substantially cylindrical shank adapted to slidably fit thebore of the spindle of the boring machine, three or more equally spacedlongitudinal grooves formed in said body member and extending into saidshank, the bottoms of said grooves being formed at an angle extendingdownwardly as the groove approaches the end of said shank which is toenter the spindle, slidable members" in each of said grooves, saidslidable members having their inner edges in contact with the bottoms oftheir respective grooves, the outer edges of said slidable members beingprovided with a recess, spring device mounted in said recess for holdingsaid slidable members against the bottoms of said grooves, and a sleeveslidably mounted on the cylindrical portion of said body member, one endof said sleeve being adapted to contact the ends of said slidablemembers to move them along the grooves and the other end of said sleevebeing adapted to contact said spindle as the cylindrical shank isinserted in the bore thereof.

4. A centering device for use with a machine spindle having a bore withrespect to the axis of which a work piece is to be positioned, saiddevice including a body member having a shank to fit into said bore andbe centered thereby, longitudinally extending grooves in said bodymember, slidable members in said grooves, each of said slidable membershaving one of their faces in sliding contact with one wall of the groovein which it is positioned, and the abutting faces of the members andgrooves being inclined longitudinally of the device, said membersincluding radial portions capable of expansion beyond the peripheralface of said device and end portions in operative association with theend portion of said spindle to cause their longitudinal movement in saidgrooves by axial shifting of said shank in said bore, whereby saidslidable members are caused to expand to engage the work piece toposition same with respect to the axis of said bore.

JOSEPH SUNNEN.

